• Title/Summary/Keyword: Gliding surface

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Reconstruction of hand using anterolateral thigh fascial free flap (전외측대퇴근막 유리피판술을 이용한 수부의 재건)

  • Kim, Ki Wan;Kim, Jin Soo;Lee, Dong Chul;Ki, Sae Hwi;Roh, Si Young;Yang, Jae Won
    • Archives of Plastic Surgery
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    • v.36 no.5
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    • pp.571-577
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    • 2009
  • Purpose: The Provision of thin and pliable tissue and the adequate coverage of tendon - gliding surface is necessary for a soft tissue defect of the hand with exposure of bone, tendon and muscle. This report will discuss our experience with anterolateral thigh fascial free flap for the reconstruction of the soft tissue defect of the hand. Methods: Between February 2004 and August 2008, seven patients with full - thickness soft tissue defects of the hand were reconstructed by means of a composite anterolateral thigh fascial free flap. There were soft tissue defects associated with trauma (n=5), scar contracture (n=1) and necrosis due to ischemia (n=1). Flaps were harvested from the anterolateral thigh as adipofascial flaps with only a small sheet of fascia and fatty tissue above it. The fascia and the skin of the donor site was closed directly and delayed split - thickness skin graft was performed. Result: All flaps survived completely. The size of the transferred flap ranged from $2{\times}4cm$ to $5{\times}8cm$. Thin flap coverage was possible without secondary debulking operations. It left minimal donor site morbidity with a linear scar. In one case, the thigh muscle herniation in the donor site was developed. Conclusion: The anterolateral thigh fascial free flap provided thin and pliable tissue which can establish a tendon - gliding mechanism, minimal bulk, minimal donor site morbidity. The disadvantages of this technique were the need for a skin graft and the muscle herniation of donor site.

How Birds and Insects Fly (곤충과 새의 비행방법)

  • Hong, Young-Sun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.10 no.1
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    • pp.130-143
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    • 2007
  • Using steady state aerodynamic theories, it has been claimed that insects and birds cannot fly. To make matters worse, insects and birds fly at low Reynolds numbers. Therefore, a recurring theme in the literature is the importance of understanding unsteady aerodynamic effect and how the vortices behave when they separate from the moving surface that created them. In flapping flight, birds and insects can modify wing beat amplitude, stroke angle, wing planform area, angle of attack, and to a lesser extent flapping frequency to optimize the generation of lift force. Some birds are thought to employ two different gaits(a vortex ring gait and a continuous vortex gait) and unsteady aerodynamic effect(Clap and fling, Delayed stall, Wake capture and Rotational Circulation) in flapping flight. Leading edge vortices may produce an increase in lift. The trailing edge vortex could be an important component in gliding flight. Tip vortices in hovering support the body weight of the hummingbirds. Thus, this study investigated how insects and birds generate lift at low Reynolds numbers. This research is written to further that as yet incomplete understanding.

Osteochondral allograft transplantation for treating medial femoral condyle subchondral bone cyst in a 14-year-old standardbred horse: a case report

  • Zsofia Pal;Gabor Bodo
    • Journal of Veterinary Science
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    • v.24 no.3
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    • pp.31.1-31.6
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    • 2023
  • Allograft arthroplasty is a promising cartilage-resurfacing technique. A 14-year-old horse was diagnosed with a medial femoral condyle subchondral bone cyst. Allografts were harvested from a young donor animal and implanted to fill the cyst cavity. A visual assessment of the surgical site was possible during follow-up arthroscopy. In addition to a desirable gliding surface and a good adaptation of the grafts, fibrillation of the cranial ligament of the medial meniscus was noted and debrided. The recipient horse became sound four months after follow-up surgery with a high level of owner satisfaction. In conclusion allograft transplantation is a promising technique for treating subchondral bone cysts.

Aerodynamics of a 2-D Flat-plate Airfoil with Tripwire (2차원 평판날개에서의 Tripwire가 공력에 미치는 영향)

  • Je, Du-Ho;Lee, Jongwoo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.16 no.4
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    • pp.575-581
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    • 2013
  • In this paper, we experimentally investigated the effects of attached cylindrical tripwires on the aerodynamic performance. The research was carried out with a simple two-dimensional (2-D) rectangular airfoil fabricated from thin flat-plate aluminium, with elliptical leading and trailing edges. Tripwires of varying widths and thicknesses, and attack angles of $-5^{\circ}{\sim}20^{\circ}$ were used to investigate the aerodynamic characteristics (e.g. lift and drag forces) of the airfoil. We found that attaching the tripwires to the lower surface of the airfoil enhanced the lift force and increased the lift-to-drag ratio for low attack angles. However, attaching the tripwires to the upper surface tended to have the opposite effects. Moreover, we found that attaching the tripwires to the trailing edge had similar effects as a Gurney flap. The aerodynamic characteristics of the flat-plate airfoil with tripwires can be used to develop passive control devices for aircraft wings in order to increase their aerodynamic performance when gliding at low attack angles.

Bacterial diseases of flounder, Paralichthys olivaceus (넙치의 세균성(細菌性) 질병(疾病))

  • Kanai, Kinya
    • Journal of fish pathology
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    • v.6 no.2
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    • pp.197-204
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    • 1993
  • Flounder culture has been developed mainly in the western parts of japan, and, to date, following six bacterial diseases have been reported. Bacterial white enteritis occurs in 16 to 30-day-old flounder larvae and often causes mass mortality in seed production. Bacterium named Vibrio sp. INFL invades and multiplies in the mucosae of posterier part of intestine, and causes desquamative enteritis. Gliding bacterial disease occurs mostly in juvenile stage and in spring to summer. Diseased signs are partial discoloration and erosion of skin and fins. Histologically, epidermis are removed, and the causative bacterium, Flexibacter maritimus, multiplies on the surface of demis and invades into the muscular tissue. Vibriosis caused by Vibrio anguillarum and related organisum is one of the well-known diseases among marine fish. Outbreaks of the disease in flounder culture are relatively few, but mass mortalities in fingerlings due to the disease were reported. An outbreak of nocardiosis in the autumn of 1984 has been reported, but since then the disease scarcely occurred. The disease is characterized by formation of abscesses under the skin and white nodes in the gill, heart, spleen and kidney. Streptococcicosis occurs frequently in recent years. Beta-hemolytic streptococcus is the causative bacterium, which possesses the same biochemical and serological characteristics as $\beta$-streptococci isolated from some marine and freshwater fish, and is seemed to related to Streptococcus iniae. Edwardsiellosis is the disease that causes most damage in flounder culture in Japan. Characteristic symptoms are swelling of abdomen and intestinal protrusion from the anus due to accumulation of ascites. Edwardsiella tarda, a well-known pathogen of freshwater fish, is the causative bacterium of the disease.

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Clinical Experiences with the Scapular Fascial Free Flap

  • Park, Il Ho;Chung, Chul Hoon;Chang, Yong Joon;Kim, Jae Hyun
    • Archives of Plastic Surgery
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    • v.43 no.5
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    • pp.438-445
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    • 2016
  • Background The goal of reconstruction is to provide coverage of exposed vital structures with well-vascularized tissue for optimal restoration of form and function. Here, we present our clinical experience with the use of the scapular fascial free flap to correct facial asymmetry and to reconstruct soft tissue defects of the extremities. Methods We used a scapular fascial free flap in 12 cases for soft tissue coverage of the extremities or facial soft tissue augmentation. Results The flaps ranged in size from $3{\times}12$ to $13{\times}23$ cm. No cases of total loss of the flap occurred. Partial loss of the flap occurred in 1 patient, who was treated with a turnover flap using the adjacent scapular fascial flap and a skin graft. Partial loss of the skin graft occurred in 4 patients due to infection or hematoma beneath the graft, and these patients underwent another skin graft. Four cases of seroma at the donor site occurred, and these cases were treated with conservative management or capsulectomy and quilting sutures. Conclusions The scapular fascial free flap has many advantages, including a durable surface for restoration of form and contours, a large size with a constant pedicle, adequate surface for tendon gliding, and minimal donor-site scarring. We conclude that despite the occurrence of a small number of complications, the scapular fascial free flap should be considered to be a viable option for soft tissue coverage of the extremities and facial soft tissue augmentation.

An External Shape Optimization Study to Maximize the Range of a Guided Missile in Atmospheric Flight (대기권을 비행하는 유도 미사일의 최대 사거리 구현을 위한 외형 형상 최적화 시스템 연구)

  • Yang, Young-Rok;Hu, Sang-Bum;Je, So-Yeong;Park, Chan-Woo;Myong, Rho-Shin;Cho, Tae-Hwan;Hwang, Ui-Chang;Je, Sang-Eon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.6
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    • pp.519-526
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    • 2009
  • This paper describes a research result of a external shape optimization study to maximize the range of the guided missile with canards and tailfins in atmospheric flight. For this purpose, the external shape optimization program which can enhance the range of a missile was developed, incorporated with the trajectory analysis and the optimization technique. In the trajectory analysis part, Missile DATCOM which utilizes the semi-empirical method was directly connected to the trajectory code to supply the aerodynamic coefficients efficiently at every time step. In the gliding flight trajectory after apogee, a maximum $C_L/C_D$ trim condition calculation module was attached under the assumption of the missile continuously flying at maximum $C_L/C_D$ condition. In the optimization part, a Response Surface Method(RSM) was adopted to reduce the computing time.

Optical emission analysis of hybrid air-water discharges

  • Pavel, Kostyuk;Park, J.Y.;Han, S.B.;Koh, H.S.;Gou, B.K.;Lee, H.W.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.521-522
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    • 2006
  • In this paper, hybrid air-water discharges were used to develop an optimal condition for providing a high level of water decomposition for hydrogen yield. Electrical and optical phenomena accompanying the discharges were investigated along with feeding gases, flow rates, and point-to-plane electrode gap distance. The primary focus of this experiment was put on the optical emission of the near UV range, with the energy threshold sufficient for water dissociation and excitation. The $OH(A^{2+},'=0\;X^2,"=0$) band's optical emission intensity indicated the presence of plasma chemical reactions involving hydrogen formation. In the gaseous atmosphere saturated with water vapor the OH(A-X) band intensity was relatively high compared to the liquid and transient phases although the optical emission strongly depended on the flow rate and type of feeding gas. In the gaseous phase discharge phenomenon for Ar carrier gas transformed into a gliding arc via the flow rate growth. OH(A-X) band's intensity increased according to the flow rate or residence time of He feeding gas. Reciprocal tendency was acquired for $N_2$ and Ar carrier gases. The peak value of OH(A-X) intensity was observed in the proximity of the water surface, however in the cases of Ar and $N_2$ with 0.5 SLM flow rate peaks shifted to the region below the water surface. Rotational temperature ($T_{rot}$) was estimated to be in the range of 900-3600 K, according to the carrier gas and flow rate, which corresponds to the arc-like-streamer discharge.

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Soft Tissue Reconstruction Using Anterolateral Thigh Flap with Fascia Lata Component (대퇴 근막이 포함된 전외측대퇴피판을 이용한 다양한 연부조직 결손의 재건)

  • Lee, Sin-Chul;Eun, Seok-Chan;Baek, Rong-Min
    • Archives of Plastic Surgery
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    • v.38 no.5
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    • pp.655-662
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    • 2011
  • Purpose: The anterolateral thigh flap is versatile flap for soft-tissue reconstruction for defects located at various sites of the body. This useful flap offers a thick and vascular fascia lata component with large amounts that can be soft tissue coverage for different reconstructive purposes. We present our clinical experience with the use of vascular fascia lata, combined with anterolateral thigh flap for various reconstructive goals. Methods: From April 2008 to February 2011, we transferred anterolateral thigh flaps with fascia lata component to reconstruct soft-tissue defects for different purposes in 11 patients. The fascia lata component of the flap was used for tendon gliding surface in hand/forearm reconstruction in 4 patients, for reconstruction medial and lateral patellar synovial membrane and retinaculum in 2 patients, for reconstruction of plantar aponeurosis in the foot in 2 patients, for reconstruction of fascial and peritoneal defect in the abdominal wall in 2 patient, and for dural defect reconstruction in the scalp in the remaining one. Results: Complete loss of the flap was not seen in all cases. Partial flap necrosis occurred in 2 patients. These complications were treated successfully with minimal surgical debridement and dressing. Infection occurred in 1 patient. In this case, intravenous antibiotics treatment was effective. Conclusion: Anterolateral thigh flap has thick vascular fascia with large amounts. This fascial component of the flap is useful for different reconstructive aims, such as for tendon, ligament, aponeurosis defects, abdominal wall or dura reconstruction. It should be considerated as an important advantage of the flap, together with other well-known advantages.